1. Field of the Invention
The present invention generally relates to initiating combustion of fuel-air mixtures. More particularly, the invention concerns a spark plug cable and a method for tuning a spark plug cable system to maximize combustion of fuel-air mixtures in internal combustion engines.
2. Discussion of the Related Art
The purpose of an ignition system is to initiate combustion of a flammable fuel-air mixture by igniting it at precisely the right moment. In spark-ignition engines, this is achieved with an electrical spark, that is, by an ark discharged between two, or more electrodes of a spark plug. An electrical potential difference, or voltage builds between the spark plug electrodes until a spark arks from one electrode to the other(s). The voltage is created by the delivery of current to the center electrode of the spark plug. A spark plug cable, or ignition wire delivers the current from a current generating device, such as a coil to the spark plug.
Combustion initiation in modern-day spark ignition engines is becoming increasingly difficult. This is because engine designs that increase fuel economy and reduce harmful environmental emissions have created unfavorable conditions for fuel-air ignition. Modern-day engines employ lean fuel-air mixtures that are difficult to ignite. Turbochargers and superchargers are also employed to increase engine efficiency. However, the increased engine combustion chamber pressures gene turbochargers and superchargers also hinder combustion. In addition, the spacing, or gap between the spark plug""s electrodes has increased, thereby increasing the amount of voltage necessary to create an ark.
The present invention solves the problem of igniting fuel-air mixtures in the difficult conditions found in modern-day engines. Broadly, the present invention provides for complete fuel-air combustion, thereby increasing engine power and decreasing harmful environmental emissions.
One embodiment of a spark plug cable constructed according to the present invention comprises a core wire extending between two ends, with one end coupled to a spark plug connector and the other end coupled to a power source. An insulator encases the core wire and a metallic sleeve encases at least a portion of the insulator. The metallic sleeve is also removeably coupled to an electrical ground. The metallic sleeve, insulator and core wire form a capacitor. An optimal capacitance value is determined by finding a maximum capacitance value and subtracting a safety margin.
Another method of the invention optimizes spark duration by coupling a resistor and a capacitor to the spark plug cable, determining an available charge from the capacitor, and selecting an ideal resistance value based on the available charge, wherein the ideal resistance value will enable the generation of a very powerful spark, thereby maximizing combustion of the fuel-air mixture.
However, the claims alonexe2x80x94not the preceding summaryxe2x80x94define the invention.